The functional binding antibodies to novel purinoceptor selected from phage display library / 中国药理学通报

ABSTRACT

Aim To screen antibodies of novel purinoceptor as a marker for further study of the purinoceptor. Method BALB/c mice were immunized for 4 times with rat aortic endothelial cell. Then the phage display system was used to construct a single-chain Fv fragment (ScFv) cDNA library from the total RNA of immunized mice. The characteristics of novel purinoceptor not existing on vascular smooth muscle cell but on aortic endothelium were used to enrich the aortic endothelium specific antibodies. Induced with IPTG, these antibodies were secreted into the periplasm of E. coli. The functional experiment of novel purinoceptor named organ bath experiment was used to screen out the positive ScFv from the soluble expressed antibodies. Immunohistochemistry experiment was used for positive ScFv identification. Results The total mouse anti-rat endothelium lgG is 1 ∶16 000. 8?106 mouse anti-rat endothelium ScFv cDNA library was successfully constructed. After 4 times of rat endothelium and rat smooth muscle cells screening, 2 500 ScFv cDNA binding membrane of aortic endothelium was enriched. After 4 times of functional screening, a phage-ScFv named B inhibiting the adenosine induced NO dependent construction by 83.4%?21.6% was selected from the expressed antibodies. Immunohistochemistry experiment showed that ScFv-B combined with aortic endothelium specifically and functional experiment showed that ScFv-B did not have any effect on adenosine induced ileum contraction, indicating that ScFv-B specifically binding to the novel purinoceptor. Conclusions ScFv-B binding specifically to the novel purinoceptor was selected by phage display technique and functional screening experiment which provide a good marker for further study of the novel purinoceptor.